The relationship between inotrope exposure, six-hour postoperative physiological variables, hospital mortality and renal dysfunction in patients undergoing cardiac surgery

INTRODUCTION: Acute haemodynamic complications are common after cardiac surgery and optimal perioperative use of inotropic agents, typically guided by haemodynamic variables, remains controversial. The aim of this study was to examine the relationship of inotrope use to hospital mortality and renal dysfunction. MATERIAL AND METHODS: A retrospective cohort study of 1,326 cardiac surgery patients was carried out at two university-affiliated ICUs. Multivariable logistic regression analysis and propensity matching were performed to evaluate whether inotrope exposure was independently associated with mortality and renal dysfunction. RESULTS: Patients exposed to inotropes had a higher mortality rate than those not exposed. After adjusting for differences in Parsonnet score, left ventricular ejection fraction, perioperative intraaortic balloon pump use, bypass time, reoperation and cardiac index, inotrope exposure appeared to be independently associated with increased hospital mortality (adjusted odds ratio (OR) 2.3, 95% confidence interval (95% CI) 1.2 to 4.5) and renal dysfunction (adjusted OR 2.7, 95% CI 1.5 to 4.6). A propensity score-matched analysis similarly demonstrated that death and renal dysfunction were significantly more likely to occur in patients exposed to inotropes (P = 0.01). CONCLUSIONS: Postoperative inotrope exposure was independently associated with worse outcomes in this cohort study. Further research is needed to better elucidate the appropriate use of inotropes in cardiac surgery.